Seismic Data Reveals Massive Avalanche Ran for 15 Minutes on Mt. Hood

It’s been a weird winter in the Pacific Northwest (PNW).

There’s no doubt that the PNW, specifically the Mt. Hood area, is used to storms coming in wet and wild, but fast and dramatic temperature fluctuations and atmospheric rivers, followed by long, high-pressure periods, have made snow and avalanche conditions particularly unpredictable.

The last couple of weeks have brought another of these prolonged high-pressure periods and warm weather to much of Oregon, California, and the rest of the West. As a result, snowpacks in some areas are starting to shed, and the possibility of wet slides has increased in these locations. On Mt. Hood, a storm brought significant precipitation in the form of snow, then rain, before making way for warm spring temperatures well above freezing in the last few days.

The Northwest Avalanche Center’s Joe Dellaporta took the opportunity to check out the damage to Mt. Hood’s snowpack on Sunday, March 22, 2026. More than 11″ of precipitation from the recent storm cycle stacked up onto a widespread crust that had been buried as of March 8th. Much of the storm came in as snow, but the last bit trended more towards rain, creating a recipe for some pretty sizeable avalanches.

NWAC posted some pretty incredible photos of an avalanche that occurred on Mt. Hood following the storm, which you can see below.

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During the storm cycle, NWAC received USGS seismic data reports, which helped determine the size and duration of avalanche activity on Mt. Hood. NWAC set out to pinpoint some of the activity recorded once things had settled a bit, and the results were pretty wild.

The USGS’s seismic data reported that a March 14 avalanche lasted for a total of 15 minutes. Further observation found that a slab that broke at 9800ft on Wy’East Face and propagated widely, running its way through Clark Canyon and stopping at 5300 ft.

In total, the slide ran 4,500 ft. Although NWAC didn’t specify exactly what the seismic reading reported, that type of measurement is usually used for earthquakes. An avalanche giving off that much energy is massive.

This slide was one of the largest recorded occurrences during the March period of activity; however, several other large slides were recorded. If you do plan to venture into the backcountry this spring, don’t forget that warming temperatures can pose just as much of an avalanche risk as new snow. Check your local forecast and recent observations as well, and never travel in the backcountry without the proper equipment, knowledge, and a buddy.

Related: Two Feet of Snow Forecasted for Washington and Oregon Ski Resorts